In IVR (Interventional Radiology) using a medical image diagnostic apparatus such as an X-ray diagnostic apparatus, there is available a function (to be referred to as an exposure distribution display function hereinafter) of displaying the distribution of exposure (to be referred to as an exposure distribution hereinafter) on an object. In the exposure distribution display function, the dose distribution of an object is displayed on one screen, as shown in each of a and b in FIG. 11.
The current exposure distribution display function, however, has a problem that it is only possible to check the exposure distribution of an object viewed from one direction. For example, an X-ray diagnostic apparatus having a single plane system has one irradiation field, and hence has no problem concerning the exposure distribution display function. However, an X-ray diagnostic apparatus having a biplane system has two irradiation fields, and hence has a problem that the operator cannot simultaneously check two irradiation fields.